Mufflers or silencers



Feb. 9, 1965 J. cRowE ETAL 3,168,935

mums on smncms 3 Sheets-Sheet 1 Filed June 18, 1962 Feb. 9, 1965 J. CROWE ET AL MUFFLERS OR SILENCERS Filed June 18, 1962 8 Sheets-Sheet 2 Feb. 9, 1965 J. CROWE ETAL 3,163,935

MUFFLERS 0R SILENCERS Filed June 18, 1962 5 Sheets-Sheet 5 United States Patent 3,168,935 MUFFLERS 0R SILENCERS John Crowe and Kenneth Arthur Wallis, Wellington, Wellington, New Zealand, assignors to Upright Scallold Lirnited, Christchurch, Canterbury, New Zealand, a corporation of New Zealaud Filed June 18, 1962, Ser. No. 293,174 24 Clm'ms. (Cl. 181- 82) This invention relates to mutllers or silencers, and has been designed particularly though not solely for use in the exhaust systems of motor vehicles.

At present motor vehicles are produced in a considerable number of makes and models and it seems that each model has a different exhaust system for the others. Consequently manufacturers must make a large variety of replacement silencers or mufiiers and also because of this stock lists must carry a larger inventory. This of course increases both the manufacturing and marketing costs.

It is therefore an object of the present invention to provide a silencer or mufller which will obviate or minimize the foregoing disadvantages and which will provide a satisfactory construction in a simple yet efl'ective manner.

Accordingly, in one aspect, the invention consists of an element for a silencer or mufiler for the exhaust system of an internal combustion engine, comprising a barrel formed at each end with a connection engaging means and a passageway through said barrel for exhaust gases, said passageway being associated with silencing or mutiling means, the construction, and arrangement being such that in use, one or more of such elements may be combined by the use of connection means engageable with the barrel thereof, and with each other when more than one of such elements is to be used, and with an inlet means and an outlet means each having connection engaging means, so that a plurality of sizes of silencer or mufller and positions and sizes of inlet and outlet pipe may be readily provided.

In a further aspect, the invention may be said to consist in a mufiler or silencer assembly for use in the exhaust systems of an internal combustion engine consisting of one or more elements constructed according to the preceding paragraph, an inlet means, an outlet means, and connecting means, said element or elements, inlet means, outlet means and connecting means being associated with each other to form said mufiler or silencer.

In a still further aspect, the invention consists of a method of forming a silencer or muffler for the exhaust system of an internal, said method comprising the steps of selecting one or more silencing elements from a stock of such elements, such stock varying in size both as to length and/or to diameter, and such silencing elements having connection engaging means engageable with connection means, connecting said elements to each other when more than one is to be used, connecting an end plate having an inlet means to one free endof the unit so made and connecting a further end plate to the opposite end, each of said connections being made by the use of connection means removably associated with said connection engaging means, said end plates being selected from an appropriate stock thereof, the connection of the various members one to the other being made in any order during assembly.

One preferred form of the invention and modifications thereof will now be described with reference to the accompanying drawings in which:

FIGURE 1 is an exploded perspective view of the parts forming a silencer or muffler according to the present invention,

FIGURE 2 is a perspective view of an assembled silencer or mufiler according to the invention with a part shown in broken section,

FIGURE 3 is an exploded perspective view of an alternative construction of a partly assembled silencer or mufller according to the present invention,

FIGURE 4 is a partly diagrammatic view showing the path of gases through a mufller or silencer using batlle plates as muflling means,

FIGURE 5 shows one type of bafile plate used,

FIGURE 6 shows a further type of bafile plate used,

FIGURE 7 shows a yet further type of battle plate used,

FIGURE 8 is a diagrammatic view illustrating a modified silencing element according to the present invention,

FIGURE 9 is a cross sectional elevation of the element shown in FIGURE 8,

FIGURE 10 is an elevation showing a clamping ring engaging an end plate to a silencing element with part shown in broken section,

FIGURE 11 is an end view of FIGURE 10, and

FIGURE 12 shows an alternative method of connecting a pipe to the end plate.

In one preferred form of the invention, a mufiier 1 for the exhaust gases of an internal combustion engine is formed with one or more silencing elements 2. The silencing element 2 comprises an outer barrel 3 having connection engaging means at each end formed by on outwardly extending annulus 4. A passage way associated with silencing or mufiring means for the exhaust gases is provided through the element 2 by a centrally positioned tubular core 5 mounted at either end by and extending through apertures in end-discs 6 which are welded or otherwise suitably attached to the barrel. The end-disc 6 has a flange 7 adapted to coact with the annulus 4 and these parts are joined, for example, by spot-welding as at 64, see FIG. 10. The core 5 is spot-welded as at 65 to the end-disc 6 at one end and sleeved through the end-disc 6 at the opposite end without positive attach ment thus allowing slight movement to compensate for any differentiation in the expansion of the various parts.

The tubular core 5 has a series of apertures 8 therein formed preferably by partially cracking-out a rectangular section around three sides and folding the cracked out portion inwardly to form louvres 9. The space between the barrel 3 and the core 5 is filled with a tire resistant sound absorbing material as, for example, a coarse, loosely packed fibre glass 10.

To meet the requirements of the various types of vehicles, the above described element is modified. Thus, an element 2a is formed with a barrel section 3 similar to that used in the above described element. The muirling means used in conjunction with the element 2:: comprise end bafile plates having a suitably shaped aperture or apertures therein. The battle plates are attached to each end of the barrel 3.

The bafile plate may be varied in shape and an example of one such baffle 12 is shown in FIGURES 3 and 7. The bafile plate 12 is formed from a blank of suitable gauge stainless steel with a relatively small central aperture 13 provided therein. Radial slits 14 extend from this aperture 13 to provide adjustable flaps 15. Preferably an even number of slits 14, such as six, are provided, and the flaps 15 formed thereby are arranged to face alternatively inwardly and outwardly. By suitable adjustment of these flaps 15, the passageway through the element 2a may be varied. The bafile 12 has a flange 16 adapted to coact with the annulus 4 on the barrel 3 with the remaining section of the bathe 12 extending inwardly i into the barrel 3 when the flange 16 is fitted in position.

A further bailie plate 17 (see FIGURE 6) is also formed from a blank of metal and is similarly shaped to the bafiie plate 12. A flange 18 is provided to abut against the annulus 4 with the remaining portion of the bafiie 17 extending slightly inwardly into the barrel 3 in use. A plurality of apertures are formed by cracking louvres 1) from the parent metal so that they remain attached along one edge to the baffle plate 17. The apertures are preferably formed in a circle near or substantially adjacent the periphery of the baffle plate 17 with the louvres 19 adapted to face inwardly into the barrel 3 in use.

A further modified form of the battle plate, designated by the reference character 20, is illustrated in FIGURE of the accompanying drawing. The bafiie 29 is formed from a blank with the flange 21 adapted to coact with the annulus 4. The remaining portion of the bafile 24) is formed as an inwardly coned section having an adjustable aperture adjacent the inner end or apex thereof. The combined length of two of these coned members must be shorter than the barrel to which they are fitted. The adjustable aperture 22 is formed by providing a series of slits 24 adjacent the inner end or apex of the cone with the flaps 23 resulting being adjustable to form a suitable aperture to provide the required passageway through the element in use. The slits 24 lie in a plane substantially parallel to the base of the battle plate Ztl.

FTGURE 4 illustrates in a partly diagrammatic form how the adjustable baffie plates provide multiple chambers for expanding and cooling the exhaust gases. In this figure, the battle plaes 2d are illustrated, although it will be realised that the bafiie plates 12 or 1'7 could similarly be used. Also, if so desired, a combination of these bafiie plates could be used in any one muliier. Thus, selected types of bailie plates as above described would be attached to each end of the barrel unit and the required number of completed elements combined to form a muffier as will be further described later.

A yet further modified element 2b is illustrated in FIGURES 8 and 9 of the accompanying drawings. A barrel 3 having annular flanges 4 is formed as was previously described. A longitudinal inner chamber 25 formed by a tubular core 26 is positioned centrally in the barrel 3. The tubular member 26 is mounted at one end by extending through a suitable centrally positioned aperture provided in an end disc 27. This leaves the end 28, protruding past the end disc 27, open to allow the entry of exhaust gases.

An end bafile plate 29 is provided at the opposite end of the barrel 5 and the tubular member 26 is supported at this'end by engaging with a centrally positioned cylindrical collar 3t? fitted to extend from the inner face of the batlle 29. This closes the opposite end of the tubular member 26 and prevents any direct passage through the element 212.

An outer chamber 31 is provided between the tubular member 26 and the barrel 3. Communicating apertures 32 along the length of the member 26 provide a path for the exhaust gases to pass from the inner chamber 25 to the outer chamber 31. The communicating apertures 32 are provided by partially cracking out a rectangular section about three sides and folding the cracked out portion inwardly to form louvres 33. In use these louvres are directed away from the entrance of gas into the chamber 25.

The bathe 29 has a plurality of apertures communicating with the outer chamber 31 formed therein. These apertures are arranged in a circle by cracking louvre 34 from the parent metal in a similar manner to that described in connection with baflle plate 17'. Thus, a path is provided through the element 21') for the gases by entering the inner chamber 25, passing through the apertures 32. to the outer chamber 31 and from the outer chamber 31 through the apertures in the battle plate 29.

All the metal parts used in the above described element are formed from a suitable stainless steel which is stronger and more resistant both to heat and corrosion than is the mild steel at present generally used in constructing known types of mutliers. The seams on the barrel 3 and the core 5 are electrically spot-welded as at 3 and 5, respectively, see FIG. 1, thus excluding any foreign fiuxing which may cause corrosion.

It will be realised that the silencing elements 2, 2a and 21) may be manufactured in various sizes and lengths but preferably the barrel 3 is approximately four inches in diameter and is manufactured to form units five inches, nine inches and 12 inches in length.

inlet and outlet means are provided for each end of an element or elements to complete the mufiier and each comprises a circular end member 37 and an outwardly extending pipe 38. The circular end member 3'7 is provided with further connection engagement means, such as a flange 39, adjacent the periphery thereof, which flange 3? is adapted, in use, to abut against the connection engagement means on one end of a silencing element 2, 2a or 212.

The pipe 38 may be fitted either centrally or off-centre of and within the member 37 by means of a suitable brace provided by, for example, a gusset 40 welded to both.

in view of the difiiculty experienced in welding stainless steel, mild steel pipes are provided extending outwardly from the end members 37. The joint between the outwardly extending pipe 38 and the end member 37, each being of dissimilar metal, is adapted to provide a positive interconnection therebetween while still allowing slight relative movement to compensate for the differential in the expansion rate of the two metals used. Thus, one joint, which will provide a suitable connection between the mild steel and stainless steel, is provided by clamping the two parts together. To this end, an annular enlargement 41 is jumped up near the end of the pipe 38 to be jointed to the end plates 37. The end 42 is then passed through a suitable aperture in the plate 37, flared outwardly and pressed in a clamp to complete the joint (see FIGURES 10 and 11). Thus, the end plate 37 is held between the enlargement 41 and the out-turned end 42. v

A further joint connecting the two dissimilar metals is provided by a weld between a nipple 43 associated with the outwardly extending pipe 38a and the end member 37a (see FIGURE 12). The end member 37a is a stainless steel member and the outlet pipe 381: is a mild steel member, as above described. The nipple 43 is also formed of stainless steel and is associated with the inside of the outlet pipe 38a at the end thereof to be attached to the end member 37a by jumping up both the nipple 43 and the mild steel pipe 38a to form an annular protuberance 44 adjacent the end of the pipe. The nipple 43 may be formed as a cylindrical section from a suitable piece of stainless steel and does not require seaming to form a complete tube. Also the nipple 43 is preferably fixed to the outlet pipe 38a by spot welding 431 to prevent relative rotation between the two. The end of the pipe 38a is adjacent the bottom of the jumped up protuberance 44 and the nipple 43 protrudes outwardly therefrom for a short distance.

An inwardly extending flange 45 surrounds the aperture in the end member 370. The depth of the flange 45 and the portion of the nipple 43 extending beyond the jumped up protuberance 44 are substantially equal. To form the protruding part of the nipple 43 is passed through the aperture in the end member 37a until the annular protuberance 44 abuts against the outer surface thereof. These members are firmly clamped in this position and positively associated with one another by spotwelding the two together as at 432. The end of the nipple 43 and the inturned edge of the flange 45 are welded together by for example gas welding. Thus, as a weld 46 is provided and, because of the nipple 43, heat resistant stainless steel metal is exposed to the exhaust gases over the Weld and on the inner surface of the outlet pipe adjacent thereto. We believe this will assist in reducing corrosion of the outwardly extending mild steel pipe 38a.

In this joint, the positive connection between the outwardly extending pipe 38a and the end member 37a is provided through the nipple 43 and by the weld 46. The relative rates of expansion between the two metals may be accommodated by the movement between the inturned flange 45 and the welded joint by such expansion tending to deform the end member 37a slightly.

As was above described with the previous type of joint, a gusset or other suitable bracing may also be used to assist in supporting the outwardly extending pipes. This bracing in both cases would be arranged to allow for the relative expansion between the two metals by, for example, providing a concavity on the end member which would also tend to further deform to accommodate the varying rates of expansion.

Various sizes of outwardly extending pipes 38 or 38a may be provided to meet the needs of most makes of vehicles. The length of the pipes may also be varied if so desired and standard lengths of, for example, four-anda-half or nine inch pipes may be provided although, as will be realised, varying other lengths may be custom built, if so required. Extra fittings, such as, for example, bent pipes, flanges, brackets, stone guards, heat deflectors and any other special fittings may of course be attached to the end member 37 or any other suitable part of the completed mulfler, if so desired.

A connection means is used to connect abutted connection engagement means and comprises a split clamping ring 47 having a substantially centrally positioned groove 48 into which the connection and engagement means may be fitted. A nut 49 and bolt 50 are provided and are adapted to pass through and coact with collars 51 on either side of the gap so that the ring 47 may be clamped together to decrease the effective diameter, thus joining the two connection engagement means.

A suitable sealing and cementing agent fragmentary rings which are shown at 160, FIG. 1, for example, a gasket cement is used on all parts fitting into the groove 48. Upon assembly, to ensure that a proper joint is formed between the connection engagement means being jointed, the clamping ring 47 is hammered into position and the nut 49 tightened. This hammering and tightening of the ring 47 is repeated until the flanges 39, 7 and 4 in the mufller represented in FIGURES l and 2 are tightly wedged into the groove 48. It is not generally necessary to fit lock nuts.

While the above described elements provide means for adjusting the tone of the muffler, it is necessary to dismantle the muffler to adjust either the flap or the louvres if the tone of the assembled mufiler is not suitable.

In use, where it is desired to assemble a silencer or muffler from the above described parts, a suitable length may be made up using one or more silencing elements 2', 2a or lb or if required a combination of these may be selected. As will be obvious from the foregoing, even allowing for the modifications above described, a relatively small stock of parts is needed to form a mufiler for almost any vehicle. The length required for any given mufiler varies both with the type of vehicle to which it is to be fitted and the type of silencing element used.

If the element 2 ten to twenty inches of element are required for engines up to fourteen horsepower, fourteen to twenty-four inches of element for engines up to twenty horsepower and eighteen to thirty-six inches for larger engines. The required length of element may be built from the modular sections kept in stock; for exam ple, three elements may be connected as shown in FIG- URE 2 of the accompanying drawings. The elements are connected together by clamping rings 47 as was above described.

The tone of the silencer or mufl'ier may be adjusted by varying the angle of the louvres 9 facing into the tube 5. In use, the louvres 9 are directed into the flow of gas passing through the tube 5 and if a quieter engine is required the louvres are bent down towards a position substantially at right angles to the main surface of the tube. This adjustment may be readily achieved by, for example, using a screw driver before the elements are assembled. It is not necessary to have the louvres 9 all inclined uniformly and, if so desired, the louvres may be turned down in oppositely disposed sections of the core to cause added turbulence in the exhaust gases passing therethrough.

The element 2a formed with either the baflle plates 12, 17 or 20 may be connected in a similar manner to that described with reference to elements 2 above. A plurality of expansion chambers is thus provided and a partly diagrammatic representation of the path through such a muffler is represented in FIGURE 4. Adjustment to the tone of the muffler may also be readily achieved with the use of this element. The flaps 15 or 23 may be adjusted to enlarge the passageway through the element 2 as was above described or the louvres 19 may be opened inwardly thus exposing a larger aperture through the end bafile 17.

The element 2b is arranged as was above described so that the inlet gases pass in through the inner chamber 25 and the tone of element 20 may be adjusted by varying the angle of the louvres 33 and 34. Because there is no direct passageway through element 2b, a shorter length of this type of element may be used to achieve the required silencing.

When the correct length of silencing element of any of the above described types has been selected and assembled, suitable inlet and outlet means are attached to each end to complete the muffler. The end members having the correct pipe sizes attached, and if required, an offset, is selected. Because the end member may be attached to the end of the element at any point, the offset pipes may be swivelled to any position in a full circle allowing a maximum number of fitting positions to be covered with a minimum possible number of parts. The standard mufller is then complete. It may have further attachments fitted if so required.

Because of the range of indepenent parts and kit-set principles used, the various parts are highly versatile. A skilled mechanic is thus able to solve any silencing or fitting problem for a car, truck, launch or even a motor mower by a suitable assembly. Also because of the adjustability in the silencing means the problem of the performance against the silencing of a motor may be resolved to the particular motorists own requirement. The three different types of elements provided and the provision for adjusting interchanging and combining them provides a maximum versatility in silencing effects attainable.

Stainless steel is fifty percent stronger than mild steel and is resistant to both heat and corrosion. Because of this the mufilers are more resistant to wear and generally have a longer life than would a mild steel mufiler. However sometimes damage is caused to the muffler by rocks or other flying objects and it is possible to replace the damaged section without having to replace the whole mufiler.

What we claim is:

1. A mufller particularly adapted for use with the exhaust system of an internal combustion engine comprising, in combination:

at least one mufiler element, said element comprising,

in turn:

a barrel having flanges extending radially outwardly therefrom at the ends thereof;

an end-disc positioned at each of the ends of said barrel, each of said end-discs having:

a flange extending radially outwardly therefrom and being particularly adapted to mutually cooperatively engage a corresponding one of the flanges at the ends of said barrel;

inlet and outlet means positioned to structurally cooperate with each of the ends of said barrel for providing the exhaust gases of said exhaust system with ingress to and egress from said mutlier element, said inlet and outlet means each comprising, in turn:

an end plate having a flange extending radially outwardly therefrom and being particularly adapted to mutually cooperatively engage the flange of a correspondingly structurally cooperatively associated one of said end-discs, and

a conduit extending axially from said end plate; and

connection means at opposite ends of the mutfler element for engaging and structurally, operatively associating the flange of a barrel end, the flange of an end-disc and the flange of one of said inlet and outlet means in gas-tight axial mutual cooperative engagement with each other, said connection means comprising, in turn:

a radially expandable annulus having a groove of such dimensional extent in each of a plurality of directions as to render the aforesaid combination of radially outwardly extending flanges disposable therewithin and generally annularly encompassed thereby;

whereby to render a plurality of mufilerrelements positionable in various combinations thereof depending upon the requisite needs of said internal combustion engine.

2. A mufiier as defined in claim 1, wherein:

said end-discs comprise:

a bafiie plate having:

a generally centrally disposed aperture, and

slits extending radially outwardly therefrom, said slits defining:

adjustable flaps therebetween, enabling the size of a passageway through said mufiler element to be varied.

3. A mufller as defined in claim 2, wherein:

the number of slits is an even number, and

the flaps are turned alternatively in each of a plurality of directions from the plane of said bafile plates.

4. A mufiier as defined in claim 1, wherein:

said end-discs comprise:

a baffle plate having:

a plurality of apertures extending therethrough and disposed in spaced relationship generally annularly about theperiphery thereof, said apertures being defined by turning louvres away from the plane of said bafiie plate.

5. A muffler as defined in claim 1, wherein:

said end-discs comprise:

a bafiie plate having:

a generally cone-shaped configuration,

an aperture positioned substantially adjacent the apex thereof and extending therethrough, and

slits extending from said aperture, said slits defining adjustable flaps therebetween enabling the dimensional extent of said aperture to be varied.

6. A muflier as defined in claim 1, wherein:

the end-disc positioned atone end of said mufiier element comprises:

a first bafiie plate having: I

a generally centrally disposed aperture, and

slits extending radially outwardly therefrom, said slits defining:

adjustable flaps therebetween, enabling the size of a passageway through said mutfler element to be varied;

and

the end-disc positioned at the other end of said mufiler element comprises:

an other bafile plate having:

a plurality of apertures extending therethrough and disposed in spaced relationship generally annularly about the periphery thereof, said apertures being defined by turning louvres away from the plane of said other bafiie plate.

7. A mufiier as defined in claim 6, wherein:

the number of said slits is an even number, and

said flaps are turned alternatively in each of a plurality of directions from the plane of said baflie plate.

8. A rnufiler as defined in claim 7, wherein:

each of said bafiie plates are configured and positioned to extend inwardly of said barrel enabling a plurality of said plates, one of which extends in a direction oppositely disposed with respect to another when a plurality of mufiler elements are axially aligned, to'

define a chamber therebetween.

9. A muffler as defined in claim 8, wherein:

the component parts and elements defined therein are fabricated of stainless steel.

10. A muffler as defined in claim 1, wherein:

each of said end-discs has an aperture extending therethrough;

a tube positioned within said barrel and being spaced annularly therefrom, said tube extending through the aperture in each of said discs and being fixed with respect to one and movably disposed with respect to an other enabling said barrel and said tube to differentially move with respect to one another as a result of differential expansion therebetween;

said tube having apertures extending therethrough and spaced longitudinally thereof and annularly thereabout, said apertures being defined by:

turning louvres from the tube inwardly and in such a direction longitudinally thereof as to direct exhaust gases passing through said tube into said apertures; and

a fire resistant sound absorbing material positioned within said barrel and about said tube.

11. A mufi'ler as defined in claim 1, wherein:

one of said end-discs has an aperture extending therethrough;

a collar positioned upon another of said end-discs and extending therefrom;

a tube positioned within said barrel and spaced annularly therefrom, said tube extending through the aperture in said one end-disc and extending to and being positioned within said collar;

said tube having apertures extendirn therethrough and spaced longitudinally thereof and annularly thereabout, said apertures being defined by:

turning louvres from the tube inwardly and in such a direction longitudinally thereof as to extend'away from the direction of travel of exhaust gases passing therethrough; and

a plurality of apertures extending through the other of said end-discs and spaced annulariy thereabout, said apertures being positioned radially outwardly of said collar enabling exhaust gases entering said tube at the end thereof extending through the aperture in said one end-disc to pass therethrough, into said barrel annularly about said tube and outwardly of said barrel through the apertures extending through theother of said end-discs.

12. A muffler as defined in claim 1, wherein:

the end plate of said inlet and outlet means is fabricated of a dissimilar material than that from which said conduit is fabricated enabling said end plate to move diiferentially with respect to said conduit as a result of diflerential thermal expansion;

a joint between said end plate and said conduit, said joint comprising:

a nipple fabricated or" the same material as said end plate, said nipple being disposed within said conduit and extending to and within an aperture extending, in turn, through said end plate,

each of said conduit and said nipple having an annular protuberance extending radially outwardly therefrom with the protuberance of the nipple being positioned within the protuberance of said conduit, said protuberance being positioned in abutting relationship with respect to said end plate, and

a connection between said nipple and a flange extending exhaust system of an internal combustion engine comprising, in combination:

a plurality of muflier elements, each of said elements comprising, in turn:

a barrel having flanges extending radially outwardly therefrom at the ends thereof;

an end-disc positioned at each of the ends of said barrel, each of said end-discs having:

a flange extending radially outwardly therefrom and being particularly adapted to mutually cooperatively engage a corresponding one of the flanges at the ends of said barrel;

inlet means positioned to structurally cooperate with an end-disc at one of the ends of one barrel and outlet means positioned to structurally cooperate with the end-disc at one of the ends of another barrel for providing the exhaust gases of said exhaust system with ingress to and egress from said muffler, each of said inlet and outlet means comprising, in turn:

an end plate having a flange extending radially outwardly therefrom and being particularly adapted to mutually cooperatively engage the flange of a correspondingly structurally cooperatively associated one of said end-discs, and

a conduit extending axially from said end plate; and

connection means for structurally operatively associating one of said plurality of muflier elements with one of said inlet and outlet means at one of the ends thereof, structurally operatively associating another of said plurality of muflier elements with the other of said inlet and outlet means at one of the ends thereof, and structurally operatively associating the remaining ends of the remainder of said plurality of muffler elements with each other, said connection means comprising, in turn:

a radially expandable annulus having a groove of such dimensional extent in each of a plurality of directions as to render the flanges of said barrel ends, the flanges of said end-discs and the flanges of said connection means disposable therewithin in various combinations thereof and generally annularly encompassed thereby;

whereby said mutfler elements are positionable in various combinations thereof depending upon the requisite needs of said internal combustion engine.

14. A muffler as defined in claim 13, wherein:

said end discs comprise:

a baflle plate having:

a generally centrally disposed aperture, and

slits extending radially outwardly therefrom, said slits defining:

adjustable flaps therebetween, enabling the size of a passageway through said plurality of muflier elements to be varied.

15. A mufiier as defined in claim 14, wherein:

the number of slits is an even number, and

the flaps are turned alternatively in each of a plurality of directions from the plane of said bathe plate.

16. A mufller as defined in claim 13, wherein:

said end-discs comprise:

a baflie plate having:

a plurality of apertures extending therethrough and disposed in spaced relationship generally annularly about the periphery thereof, said apertures being defined by turning louvres away from the plane of said baflle plate.

17. A mulfler as defined in claim 13, wherein:

said end-discs comprise:

a baffle plate having:

a generally cone-shaped configuration,

an aperture positioned substantially adjacent the apex thereof and extending therethrough, and

slits extending from said aperture, said slits defining adjustable flaps therebetween enabling the dimensional extent of said aperture to be varied.

18. A mulfler as defined in claim 13, wherein:

the end-disc positioned at one end of each of said plurality of muflier elements comprises:

a first baffle plate having:

a generally centrally disposed aperture, and

slits extending radially outwardly therefrom, said slits defining:

adjustable flaps therebetween, enabling the size of a passageway through said muffler elements to be varied; and

the end-disc positioned at the other end of each of said plurality of muffler elements comprises:

another bafiie plate having:

a plurality of apertures extending therethrough and disposed in spaced relationship generally annularly about the periphery thereof, said apertures being defined by:

turning louvres away from the plane of said other baffie plate.

19. A muffler as defined in claim 18, wherein:

the number of said slits is an even number, and

said flaps are turned alternatively in each of a plurality of directions from the plane of said bafiie plate.

20. A muffler as defined in claim 19, wherein:

each of said baflie plates are configured and positioned to extend inwardly of the barrel with which they are structurally operatively associated enabling a plurality of said plates, one of which extends in a direction oppositely disposed with respect to another, to define a chamber therebetween.

21. A muflier as defined in claim 20, wherein:

the component parts and elements defined therein are fabricated of stainless steel.

22. A muffler as defined by claim 13, wherein:

each of said end-discs has an aperture extending therethrough;

a tube positioned within said barrel and being spaced annularly therefrom, said tube extending through the apertures in each of said discs and being fixed with respect to one and movabiy disposed with respec to another enabling said barrel and said tube to differentially move with respect to one another as a result of differential expansion therebetween;

said tube having apertures extending therethrough and spaced longitudinally thereof and annularly thereabout, said apertures being defined by:

turning louvres from the tube inwardly and in such a direction longitudinally thereof as to direct exhaust gases passing through said tube into said apertures; and

a fire resistant sound absorbing material positioned within said barrel and about said tube.

23. A mufiler as defined by claim 13, wherein:

one of said end-discs has an aperture extending therethrough;

a collar positioned upon another of said end-discs and extending therefrom;

a tube positioned within said barrel and spaced annullarly therefrom, said tube extending through the aperture in said one end-disc and extending to and being positioned within said collar;

said tube having apertures extending therethrough and spaced longitudinally thereof and annularly thereabout, said apertures being defined by:

turning louvres from the tube inwardly and in such a direction longitudinally thereof as to extend away from the direction of travel of exhaust gases passing therethrough; and

a plurality of apertures extending through the other of said end-discs and spaced annularly thereabout, said apertures being positioned radially outwardly of said collar enabling exhaust gases entering said tube at the end thereof extending through the aperture in said one end-disc to pass therethrough, into said barrel annularly about said tube and outwardly of said barrel through the apertures extending through the other of said end-discs;

the one end-disc of one of said plurality of mufiier elements defining with and between the other and apertured end-disc of another of said plurality of mufiier elements a chamber enabling exhaust gases to pass through the apertured end-discs of one of said plurality of mufiier elements into and within the tube of a succeeding one of said plurality of niufiler elements.

24. A rnuiiier as defined by claim 13, wherein:

the end plate of said inlet and outlet means is fabricated of a dissimilar material than that from which said conduit is fabricated enabling said end plate to move differentially with respect to said conduit as a result of di'derential thermal expansion;

21 joint between said end plate and said conduit, said joint comprising;

a nipple fabricated of the same material as said end plate, said nipple being disposed within said conduit and extending to and within an aperture extending, in turn, through said end plate,

each of said conduit and said nipple having an annular protuberance extending radially outwardly therefrom with the protuberance of the nipple being positioned within the protuberance of said conduit, said protuberance being positioned in abutting relationship with respect to said end plate, and

a connection between said nipple and a flange extending inwardly of said end plate and defining the periphery of said aperture; and

a brace extending from said conduit to said end plate and being connected thereto;

said conduit being positioned eccentrically of said end plate enabling the conduit of said inlet means and the conduit of said outlet means to be positioned annularly variably with respect to one an other.

References Cited by the Examiner UNITED STATES PATENTS 1,541,275 6/25 Powell 181-63 1,607,146 11/26 Bauroth. 2,019,746 11/35 Tatter 181-61 2,05 4,324 9/ 3 6 Hollerith 181-49 2,115,128 4/38 Starkweather et a1. 181-57 2,196,920 4/40 Hoyle 181-36 2,511,190 6/50 Wright 181-63 2,570,728 10/51 Storey 181-47 2,583,366 1/52 Engels 181-42 2,93 6,846 5/60 Tyler et al. 181-60 3,106,984 10/63 Carter 181-63 LEO SMILOW, Primary Examiner.

C. N. ROBINSON, Examiner, 

1. A MUFFLER PARTICULARLY ADAPTED FOR USE WITH THE EXHAUST SYSTEM OF AN INTERNAL COMBUSTION ENGINE COMPRISING, IN COMBINATION: AT LEAST ONE MUFFLER ELEMENT, SAID ELEMENT COMPRISING, IN TURN: A BARREL HAVING FLANGES EXTENDING RADIALLY OUTWARDLY THEREFROM AT THE ENDS THEREOF; AN END-DISC POSITIONED AT EACH OF THE ENDS OF SAID BARREL, EACH OF SAID END-DISCS HAVING: A FLANGE EXTENDING RADIALLY OUTWARDLY THEREFROM AND BEING PARTICULARLY ADAPTED TO MUTUALLY COOPERATIVELY ENGAGE A CORRESPONDING ONE OF THE FLANGES AT THE END OF SAID BARREL; INLET AND OUTLET MEANS POSITIONED TO STRUCTUALLY COOPERATIVE WITH EACH OF THE ENDS OF SAID BARREL FOR PROVIDING THE EXHAUST GASES OF SAID EXHAUST SYSTEM WITH INGRESS TO AND EGRESS FROM SAID MUFFLER ELEMENT; SAID INLET AND OUTLET MEANS EACH COMPRISING, IN TURN: 